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Monday, June 13, 2011

Isn't it fun when you think you know the ins-and-outs of a technology, then run across something that fundamentally has you scratching your head in confusion? You've been working with a technology for quite some time and you think you've seen it all, or at-least heard about it all if you haven't had the need to work with specific pieces.

In Wi-Fi we learn a lot about how decibels measure relative, not absolute, power output in relation to some other reference point. We have dBi (isotropic radiator), dBm (1-milliWatt), dBd (standard dipole antenna), etc. These are known quantities, and most Wi-Fi professionals worth a lick can run circles around antenna azimuth or elevation patterns and specifications using these units of measurement. We get them, we know them, we are "comfortable" with them.

Then something comes along and throws us off our game, and pushes us to question our own basic understanding of the universe of Wi-Fi (Hey, that's kinda catchy: "universe of Wi-Fi". I might have to start using that phrase). Such was the case last week for me. It all revolves around the db-MEG. "dB-what?" That was my first reaction too!

Vehicle Mounted
Mobile Device

Let me provide a little bit of background. The retail organization where I work owns and operates dozens of Distribution Centers (warehouses) that accept bulk product, process, and ship it out to hundreds of stores apiece. These warehouses have yard hostlers, essentially trailer cabs that ferry semi-trailers to/from parked positions and dock doors. These cabs are outfitted with rugged vehicle mounted mobile devices with a cable lead for an external antenna mounted on the roof of the cab. Since the mobile device in question only provides a single external antenna lead, signal reception (or lack thereof) becomes an important consideration given the lack of antenna diversity. Now, these devices have been around for a while and mobile device selection and ownership are owned by a partner team, not the Wireless Engineering team directly. Additionally, they were deployed before I joined the team.

Laird Phantom Antennas

The vehicle mounted mobile devices in the yard were installed with Antenex / Laird "Phantom" antennas (we also have more of these mobile devices inside the warehouse, but they are in operation with the built-in omni-directional antennas). These antennas are manufactured for use in mobile vehicular environments, typically in urban environments with high amounts of RF signal reflection, refraction, diffraction, and scattering. Additionally, these antennas don't use typical units of measurement, they use a new gain specification called the dB-MEG. It appears that this technology has actually been around for a while, referencing an IEEE paper from 1990. The vendor (Antenex / Laird) claims that these Phantom antennas provide "a radiation pattern tailored to the mobile environment" by tuning the directivity and polarity of the antenna.

Decibels Mean Effective Gain is used by one manufacturer. To establish the Mean Effective Gain for their antenna, received power is first measured and averaged using a ¼ wave whip (0 dBi) in a real mobile or reflective environment.

The whip is then replaced with their antenna, and again measured in the same environment.

The MEG gain is then the ratio of the two received powers. On average their antenna receives twice the power of the ¼ wave whip in a mobile or reflective environment. Alternatively said, their antenna has 3dBi Mean Effective Gain.

Here are sample specifications from one such antenna that we have in-use in our environment:

Laird TRAB24/49003P Sample Antenna Specifications

Intermittently, we have problems with these devices dropping connection during roaming events. After we verified adequate coverage, ruled out interference, ran active tests and debugged the connection, I am ultimately questioning adequate signal reception by the client. Given two things really leads me to this conclusion: 1) The mobile device does not support diversity with external antennas, and 2) these Phantom antennas have lower gain than dipoles (when measured in dBi) and not quite omni-directional beamwidths. I can understand why our partner team chose these models, they are seemingly a good fit for mobile vehicles. However, their intended application in urban environments with high signal reflectivity and multipath is not even close to the same use-case as our warehouse shipping and receiving yards in rural American locations with vast wide-open spaces, fluctuations in trailer density in the parking lot, and minimal multipath. I am questioning whether the antenna radiation patterns (shown above) are causing the intermittent signal drop-out.

The problem isn't licked yet, but running across something new like dB-MEG presents a previously unknown variable to consider. I wasn't aware of this measurement unit in the market, and wouldn't have been unless I had run across this issue with an already deployed product in our environment or worked on an urban outdoor mobile vehicular project of some sort.

I'm still learning about these Phantom antennas, and have many more questions. However, based on these specifications and our performance issues, I'm not sold on their application in our environment.

I've added dB-MEG into my arsenal of Wi-Fi acronyms, even if it's categorized in the "nice to know, but not really useful" section.

Wednesday, June 8, 2011

Last month I ran a short 1-question survey, asking readers to rate the importance of various factors when selecting a wireless LAN vendor. I received 95 responses, which was pretty good turn-out for an informal survey on my little corner of the blogosphere. Thank you to all that responded to the survey!

The survey results are in, and here are the findings.

Note - This was NOT a scientific survey. These results only indicate the importance of criteria based on the survey respondents.

Survey Question:What are the most important factors that influence wireless LAN vendor selection?

Rating Levels:

Not Considered

Low

Average

High

Critical

Survey Results
Survey responses revealed the following average ratings for each factor:

Survey Results - Importance of Various Factors When Selecting a WLAN Vendor
(click to enlarge)

Detailed response breakdown:

Survey Results - Complete Response Breakdown
(Click to Enlarge)

The Most Important Criteria

Product Quality Assurance & Stability scored the highest, with an average rating of 4.24. Additionally, this factor received the most "Critical" rating accounting for 40% of all responses for this item. Clearly customers want bug-free code and network stability from their vendor of choice. Vendors should not lose focus on product quality in order to speed time-to-market, especially if that means sacrificing development, code review, QA testing, or customer trials (alpha / beta).

Vendor Technical Expertise also scored really high, with an average rating of 4.16. This factor received over 83% of responses for either "High" or "Critical" importance. This points to a strong need to leverage professional services for WLAN installations. Given the relative complexity of deploying high-performing wireless networks, the growing demand for Wi-Fi networks, and the explosive growth of mobile devices, this is not surprising. Many customers are not equipped with the resources to handle these projects and need to lean on vendors, partners, and managed service providers for technical Wi-Fi expertise. Expect continued substantial compound annual growth rate (CAGR) for professional services in the industry.

Solution Scalability is important for customers as networks grow. Based on the response breakout, solution scalability appears to be applicable to more customers than either Product Quality Assurance & Stability or Vendor Technical Expertise, having over 88% of responses rated "High" or "Critical". However, customers concerned about QA/stability and vendor expertise rated those as "Critical" more often than scalability. There is no doubt that the WLAN industry is seeing tremendous growth in product shipments since the release of 802.11n, and despite the recent economic recession. Customers are expanding networks, adding coverage and capacity, and require solutions that can handle increasingly large network deployments effectively.

Support Response Time & Escalation are also highly important, with over 50% of responses rated as "High" and 27% as "Critical". Customers require qualified vendor support and rapid escalation and remediation of issues to minimize network disruptions. Just as many organizations are relying on outside expertise for professional services during network design and installation phases, similar expertise is required for post-sales support and incident response.

Other notable important items include:

Vendors should provide easy access to Product Documentation. Vendors should not require current support contracts, or make customers create an account on the website to access documentation. By doing this, vendors make it difficult for customers to be self-sufficient from a support perspective, place roadblocks and barriers in front of valuable training resources, increase vendor support costs, and limit publicly available information that potential future customers could use to become more familiar with your products. Vendors only hurt their own existing customers and future product sales by doing this (or they have something to hide that they don't want competitors to see, which they will eventually anyways).

A solid Management Platform will include features to monitor, configure, report and alert on all features within the network products. Vendors need to place appropriate resources into network management systems to ensure customers are able to effectively use and manage their products without requiring advanced technical skill sets. Often times, organizations utilize experts for initial deployment, then turn over day-to-day management and support to less experienced or less specialized teams (provisioning, help desk, etc.). Vendors should enable these teams to mange the network in an easy-to-use fashion that is intuitive and requires a minimal learning curve.

Hardware and Software Maintenance Structures are important for customers as they continue to get more sophisticated in TCO analysis and look for ways to minimize Operational Expenses (OpEx) over the lifetime of the product deployment. Vendors will need to offer solid value propositions for hardware and software warranty policies or face significant push-back from customers. This has already been reflected in the industry as multiple vendors are now decoupling hardware from software maintenance contracts, offering customers the flexibility to choose an equipment sparing and support strategy that meets their needs. Expect increased scrutiny of software maintenance structures (including licensing) as customers look to simplify financial analysis and avoid getting nickel and dimed for table-stakes features or support that may be deemed unnecessary.

Wireless network Architecture Approaches are gaining increasing visibility within the industry, as small vendors hammer the drum on controller-less architectures and big vendors continue to develop distributed solutions to handle increasing traffic loads with 802.11n, 802.11ac, and 802.11ad which are quickly complicating current controller-based models. Increased importance on this topic is expected as network loads and utilization continue to increase and as industry analysts continue to highlight the diverging approaches within the industry. This will be a make-or-break decision point for many customers, especially customers with highly distributed environments.

Least Important Criteria

Maintaining a Single Vendor Network was the least important factor for most respondents, with 10% rating it "Not Considered" and 26% rating it "Low". However, a small contingent of respondents do factor this into their decision process with 26% rating it "High". Based on these two opposing viewpoints this is a divisive subject with large variability between customers. Clearly there are two camps of thought on this topic. This leads me to believe that the single vendor mantra may hold more weight when specific requirements must be met or in environments where a clear value proposition exists. This value could stem from many different points, including process efficiencies, integration capabilities, reduced duplication of effort to support multiple products with varying capabilities, or reduced workload training and supporting a complex environment, etc. However, for customers without a clear requirement or value proposition, this factor holds little weight.

Vendor Market Share and OEM Relationships are not critical to the vendor selection decision. This highlights a great opportunity for smaller vendors to increase customer base through both overall market expansion as well as in direct competitive sourcing events. This also highlights the highly competitive nature of the Wi-Fi market today and the need for continuous improvement by all vendors to stay relevant.

Other Trends and Implications

First, vendor RF and security feature differentiation are still a significant factors in the WLAN industry. However, customers appear more willing to accept vendor roadmaps for feature parity rather than jumping to a competitor to acquire a single innovative feature. Customers are evaluating complete solutions, and barring a "killer" feature, will give vendors time to develop comparable features. With most vendors utilizing merchant silicon, time to market for most features are now relatively quick based on software development timelines. Vendors that can differentiate based on fundamental architecture approaches or hardware capabilities will stand to gain more competitive advantage than vendors focusing on software feature innovation.

Second, advanced wireless services such as Real-Time Location Services (RTLS), Guest Wi-Fi (hotspots, partner access), and wireless intrusion prevention services (WIPS) are of increasing relevance to customers as IT departments move beyond providing basic network connectivity and evolve into more of a service organization. Vendors must either dedicate resources to develop integrated value-add wireless services and capabilities, or establish over-the-top capabilities through strong ties with 3rd party best-of-breed solutions including strong systems integration to present a unified and cohesive platform for the customer.

Finally, the need for quality Wi-Fi training has never been more apparent. Heavy reliance by many organizations on external professional services highlights the demand for qualified Wi-Fi expertise and an insufficient number of experts available in the industry. If you're looking for quality training for yourself or your staff, check out my Wi-Fi Training Resources page.

Revolution or Evolution? - Andrew's Take
Although most vendor announcements, press releases, and industry analysis focuses on the latest wireless features, many customers still make decisions based on fundamental "critical factors" that directly impact their ability to conduct business. Vendors should ensure that innovation does not come at the cost of stability, and should focus heavily on professional services as customers require help to deploy next-generation wireless networks. This is a time of tremendous growth, competition, and innovation within the Wi-Fi industry. Technical Wi-Fi skill sets are in high demand, and the industry collectively needs more qualified experts to meet this demand. When the global economy stumbled through the recession, Wi-Fi kept going relatively strong. As the economy slowly emerges, this industry is set to explode! Small vendors will be growing rapidly, trying to sell customers on different architectural approaches and feature innovation. Large vendors will be expanding customer bases through established sales channels and selling advanced professional services. Customers will be buying, buying, buying, like crazy.

Customers - do you have well-defined requirements?
Vendors - do you have an appropriate market strategy to sell customers on your solutions?

I welcome reader feedback and thoughts? Do these results match your expectations? Are any important criteria missing that you would consider for vendor selection?

I ran an admittedly unscientific survey about WLAN Vendor Selection Criteria and decided to giveaway a CWDP Study Guide in the process. Although the response period is over, I am compiling the survey responses and will post the results soon - stay tuned!

Small market Wi-Fi vendors like Aerohive have a knack for pushing the industry forward. They are willing to take a fresh approach and are much more agile at adapting to market demands than larger vendors. I think their Credential Caching capability is a feature that provides a great value for customers and makes other vendors look out of touch with true branch environment needs. Abby at Aerohive also seems to agree (imagine that)!

Stephen Foskett covered Apple's new AirDrop feature which is forthcoming with Mac OS X 10.7 "Lion", and broke the unfortunate news that once-again, they are relying on proprietary protocols to accomplish their goals. Why, oh why, can't they just use Wi-Fi Direct?

The Packets Never Lie, at least according to Douglas Haider. This was a fun little video that Kevin Sandlin at CWNP, Inc. put together from the CWAP beta class attendees.

Techie Wi-Fi Articles:

Sam Clements busted out some Linux kung-fu on Cisco networking equipment to resurrect an NM-AIR-WLC6 from death. He reminds us just how useful some basic Linux skills can be as a swiss-army knife for many occasions as an IT professional. And that "dd" is our friend :)

The guys at MetaGeek give practical advice on building a spectrum analysis report with their Chanalyzer Pro Report Builder. Remember, include only the appropriate amount of data and graphs to get your point across. Too much data can be self-destructive!

Aerohive released HiveOS 4.0, which includes enhanced support for Mobile Internet Devices (MIDs), spectrum analysis based on the Atheros chipsets, and Partner Admin which enables managed service provider cloud NMS control for customer deployments. See reviews by Chris Lyttle and Marcus Burton.

PC Pro (a UK based magazine) researched What's Killing Your Wi-Fi? This article is full of so many mistakes, mis-conceptions, and flat-out wrong advice, that I would caution anyone reading it to dismiss most of what it says. From getting the unlicensed frequency ranges wrong, describing co-channel interference of other Wi-Fi networks minimal compared to non-Wi-Fi interference, to coming dangerously close to advising users to leave their networks unsecured for performance gains, PC Pro shows very poor journalism. I also would like to know what "wireless industry experts" they "canvassed", because they don't site any sources (other than generically) and their facts are incomplete or wrong in many cases.

Other IT Related Articles:

Riverbed unleashes the fury on competitors paying for so-called "independent lab testing", which is arguably skewed to shed favorable light on the sponsoring vendor's products. I think we've all read these types of reports, and most of us are smart enough to see through them. However, it's unfortunate that some customers will never know better, and take these reports at face value. Matthew Norwood also recently called out the need to study vendor solutions and be careful who you trust prior to making decisions. Bravo Riverbed and Matthew!

My good friend, Nate Lee, covered ARP Spoofing / Man-in-the-Middle attacks, DHCP Snooping, and Dynamic ARP Inspection security controls on wired switches. This is a great intro to these network security features that all organizations should consider implementing on edge access switches. This must be his way of showing me how secure his network can be after I've heckled him for years about how my Wi-Fi network was much more secure than his wired network :)

FCC Commissioner Mignon Clyburn visited my hometown of Omaha, NE and spoke about broadband availability being so much more than just access to the Internet. The Internet is already a necessity for almost everyone to function in today's society. She spoke of the issues of physical broadband availability, adoption, and important access provided by local libraries, schools, employers, friends and families. Also of critical importance, especially in rural America, is access to distance learning programs for children and students (something which I am proud to have worked on at my time early in my career with a local NE school district).

I will be attending Cisco Live! 2011 in Las Vegas, NV between July 8-15th. This will be my first ever trip to Networkers / Live and I am excited to see what the event has to offer. Working for a customer has typically limited how many individual seats we are able to send to the event due to staffing requirements back at the office and funding for travel and expenses. I've heard many good things over the years, along with some cautionary tales, tips, and tricks to get the most out of the event.

Here is my schedule for the event (emphasis on topics added by me):

Friday / Saturday

Fly into Las Vegas on Friday (time TBD), get settled into the hotel, and network with other peers that may be travelling in early.

If anyone is available on Friday or Saturday to network, hit me up via email or twitter (@revolutionwifi).

Sunday

08:00 - 17:00 TECSEC-2041 Identity and Security Group Access with 802.1X and TrustSec

This session is a deep dive on 802.1X and the technologies that make up Cisco’s TrustSec solution. This includes the functions of access control and the application of policy derived from end-point profiling, Security Group Tags (SGTs), Network Device Admission Control (NDAC), guest access, change of authorization, and MACSec. With these technologies businesses can address many existing and emerging network access control issues, such as regulatory compliance, virtualization, and guest services. A basic knowledge of 802.1X is assumed.

I decided to go with the ISE / TrustSec technical session on Sunday, instead of the CCIE Wireless session. With the growing explosion of mobile devices in corporate environments, understanding the latest context-aware security architectures is a must in my current position. I've already acquired my CCIE digits, so real-world applications of ISE / TrustSec take priority over an exam refresher.

Attendees will be given a comprehensive walk through on the technology and design that enables Cisco’s WLAN solution to support tablets and other mobile devices while still providing appropriate performance, security and quality of service for the user. The session starts with an exploration of 802.11n and CleanAir, highlighting deployment best practices and an exploration of the client capabilities in tablets today. Second, the topic of strong authentication will be discussed along with advanced policy capabilities leveraging device fingerprinting to identify who and what is accessing the network with an example from a real-world customer case study. Next, the topic of multicast best practices over wired and wireless networks will be explored as a means of delivering high-quality video to many users. Lastly, the session will culminate with quality of service implementation guidelines for the end to end solution to properly meet the demands of challenging applications like voice and video while contending with the ever present needs of reliable data service.

This session should provide a nice transition from the previous day session on ISE / TrustSec with real-world application of the solution to support a large enterprise WLAN environment. Additional topics include multicast and QoS considerations, which are typically very difficult solutions to architect for large customers and require extensive planning and expertise. As a bonus, my local wireless CSE, Alex, is one of the presenters!

Tuesday

08:00 - 09:30BRKEWN-2019 Managing the Mobile Device Wave: Best Practices
Learn how to plan, evaluate, and implement wireless in demanding high density environments such as lecture halls, classrooms, and auditoriums. Learn how to evaluate end user throughput requirements and translate this into the number of channels required. Learn how to manage cell size, co-channel interference, and successfully apply these principles using Cisco's Unified Wireless Network.

10:00 - 11:00GENKEY-4700 Welcome and Keynote Address

Come hear John Chambers paint a compelling picture of the future of networking and communication technology and the ways it will transform business practices, education, and social relationships. He will help you put your week of learning and training into the broader context of the industry’s evolving future.

12:30 - 14:30BRKEWN-2010 Design and Deployment of Enterprise WLANs

This session focuses on design and deployment concepts for enterprise and branch office WLAN deployments, i.e. the core technologies that drive and enable mobility services. Topics covered include protocol comparisons between LWAPP and CAPWAP, deep-dives into new controller features, mobility protocols and design recommendations, and the latest in design and deployment recommendations for new WLAN controllers, including centralized and distributed deployments.

16:00 - 18:00PNLUCC-4004 The Workforce of the Future

Today’s younger generations are technically savvy by default. Video and social networking are how they collaborate. As this new talent enters the work force, what will they expect? In what ways are you calibrating your global IT infrastructure to accommodate for changing work patterns and demands for any device on the network from anywhere? Follow-the-sun, 24-by- 7 work time is upon us now. With talent pools spread across the globe, what architectural strategies will work best for your enterprise to ensure employees can collaborate, innovate and execute with the highest levels of productivity? This panel of experts will discuss how to approach these questions, touching upon security, video, collaboration tools, and more.

20:00 - 24:00Private CCIE Party!!!

I'll cap off the day by attending the private CCIE party. I can't wait to network with other brilliant minds. I wonder what I should wear?

On Tuesday, I will be focusing on wireless network performance with the onslaught of mobile devices, both personal and corporate liable. Managing high density network performance is critical given the growth of enterprise and public WLAN deployments needing to support smartphones, tablets, netbooks, notebooks, and other consumer electronics. In addition, the method by which we work and collaborate at work is merging with how we conduct our personal lives. Technology solutions are blurring the line, and the it is important to understand how to enable younger generations of workers that integrate technology much more deeply into their lifestyle.

This session focuses on the architecture concepts of the branch office WLAN deployments, emphasising the core technologies that drive and enable mobility in retail, banking, education, entreprise or managed wlan services. Topics covered include in-depth protocol description of H-REAP (FlexConnect), all deployment options in practice, and are based on customer case studies for their application into the branch environment.

10:30 - 11:30GENKEY-4701 Cisco Technology Keynote

12:30 - 14:30BRKEWN-2011 Managing an Enterprise WLAN with Wireless Control System (WCS)

This session focuses on Wireless Control System (WCS) as a deployment, management, and troubleshooting tool for Cisco Unified Wireless Networks.

Managing the Radio Frequency and Spectrum is a critical challenge for modern WLAN networks, especially with advanced applications like VoWLAN. This session looks at the theory of operations and best practices for taking advantage of Radio Resource Management and usage of several tools included or available from Cisco like 'Planning Mode' and 'Cisco Spectrum Expert'. This session is updated to reflect new advances contained in release 7.0 of CUWN, and is of an advanced level.

On Wednesday, I will be focusing on branch office WLANs, a topic near and dear to my heart working for a large retail organization. I will be interested to hear the latest information on the Flex 7500 controller platform and applications in branch environments. Second, I'll be interested to hear about network management with the WCS platform, and hopefully, a healthy amount of detail surrounding the new Cisco Prime NCS platform that will replace WCS (despite not being listed in the session description). Finally, I'll wrap up with some more RF performance considerations, including spectrum analysis.

Thursday

09:00 - 10:00BRKCDN-1111 Evolution of the CCX Program and Services Solutions

Cisco has driven Enterprise WiFi thought leadership since 2001 and offered the Cisco Compatible Extension (CCX) program as a pre-standard innovation program to certify that Cisco and third party WiFi devices are “Cisco Compatible” (CCX Certified) and take advantage of Cisco innovation in the WLAN Infrastructure and the extension to Wireless Carriers (Hotspot 2.0). If your company makes WiFi enabled devices, attend this session to learn more about the latest innovation and schedules of the CCX Program and how Cisco continues to lead with pre-standards innovation in laptops, tablets, dual mode phones, digital media players, medical devices and anything WiFi. Also, learn about how the Cisco Developer Network (CDN) Program is evolving include application solutions from partners from the "client to the cloud".

10:30 - 11:30GENRST-4640 Town Hall: Borderless Networks

12:00 - 14:00BRKSEC-3005 Advanced IEEE 802.1X for Wired Networks

This session builds on the concepts introduced in BRKSEC-2005, with a focus on design optimization and troubleshooting IEEE 802.1X. Drawing on real-world examples, we examine complex system interactions that can occur when deploying IEEE 802.1X and how to prepare for those situations. We take another look at the three deployment models introduced in BRKSEC-2005 (Monitor Mode, Low Impact Mode, and High Security Mode), focusing on best practices, benefits, limitations, and advanced features such as MACSec and NEAT. The session will also address how to troubleshoot common problems in each model, including authentication failures, authorization failures, IP telephony failures, and other complex system interactions. Understanding of IEEE 802.1X is required, BRKSEC-2005 is recommended.

The proliferation of Wi-fi enabled devices creates important challenges for IT, perhaps the chief challenge being security and scalable, efficient, secure roaming. This session will cover the state-of-the-art technologies for proper authentication and encryption and fast, secure roaming. Topics include 802.11i/WPA/WPAv2, TKIP/AES & Fast roaming with CCKM, PKC, and the emerging 802.11r standard. Different EAP types like PEAP, PEAP-GTC, EAP-TLS, EAP-TTLS, EAP-FAST will be covered in this session. The session will include best practices for implementing latest WLAN security techniques and design and deployment recommendations for device roaming.

On Thursday, the final event day, I'll be focusing on wireless client performance optimization with the CCX program and secure fast roaming. Sandwiched in-between, I'll dip into a session on wired 802.1X, which is gaining momentum in large organizations that are finally realizing their physical controls are insufficient and need to place more controls around enterprise wired switch ports. Perhaps organizations are also realizing just how secure the wireless network has become and are jealous!

I'm excited to be going to the event for the first time! See you networking nerds at the event! (yes Tom, this means you).